Really? How old are you? In my case, I tried to surprise GM Gustaffson with the Urusov gambit in a bullet game but he beat my anyway. I also played IM Michael Rahal in blitz, and at least reached an endgame
Have you ever played a Grandmaster ?

In tournaments, I have played pretty much all of the US GMs from the earlier generation who were top in the 90s (Kaidanov, Yermo, Kudrin, Fedorowitz, Benjamin, DeFirmian, Goldin, Ivanov, Serper, etc.) but, interestingly, none of the current top US GMs. (I played Nakamura once online and Shankland once long before he was a GM, so that doesn't count). Of GMs who were legendary in some ways, Psakhis (1/2-1/2), Lembit Oll [RIP] (0-1), Gufeld [RIP] (1-0), Wojtkewitz [RIP] (0.5-1.5), Lputian (1/2-1/2), Bisguier [RIP] (1/2-1/2).

Way back when I first started at this website in 2016, I played not a Grandmaster but National Master (NM - and yes, he was apparently certified as the real deal by the website). He blew his queen 5 moves in and resigned on the spot. I wish every NM would do that when they played me, but I really have to think it was a fluke. He was probably exhausted from a long day and I just got lucky. This must happen to Magnus on occasion as well. Must be pretty embarrassing when it does!
I have not in person per se, but exactly 20 years ago to this day (7-FEB-2003) I was on the Deep Junior team playing against Garry Kasparov in game 6 of what then was the Man vs. Machine world championship. It was super humbling to get to work with Amir and Shay as well as see Kasparov in action against DJ. Here is the recap:
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be2 e5 7. Nb3 Be7 8. O-O O-O 9. Kh1 Bd7 10. Be3 Bc6 11. Bf3 Nbd7 12. a4 b6 13. Qd3 Bb7 14. h3 Rc8 15. Rad1 h6 16. Rfe1 Qc7 17. g3 Rfd8 18. Kh2 Re8 19. Re2 Qc4 20. Qxc4 Rxc4 21. Nd2 Rc7 22. Bg2 Rec8 23. Nb3 Rxc3 24. bxc3 Bxe4 25. Bc1 Bxg2 26. Kxg2 Rxc3 27. Ba3 Ne8 28. f4 Game drawn 1/2-1/2
A funny mention of that match, it was broadcast live on ESPN and in the first game, Junior was taking it's time on an eval and you have never seen producers go berserk like you have when the live feed went black! Everyone began stressing (except for the players) to diagnose/fix the issue and wanted to restart the game. I asked them to wait and realized it was just the machine moving to hibernate while Junior was thinking. A quick move of the mouse was the solution.
Cheers,
Scott
I have defeated CM in a simul